Fluid pressure regenerator and process

ABSTRACT

A fluid pressure regeneration process and apparatus useful in alternating high and low pressure cycle fluid systems comprising one or more valve means each of which in succession sequentially transfers into a series of storage vessels, each being isolated from the other and from the alternating fluid system by said valve means, successive fractional portions of the fluid exhausted from the alternating fluid system, during transition from the high pressure cycle to the low pressure cycle. Each such storage vessel has a different final pressure sequentially becoming lower with reduction of pressure in the alternating fluid system. Each isolated storage vessel contains and stores a fractional portion of the fluid. Recovery of the same fluid portions may be achieved by providing communication of each storage vessel with the alternating fluid system through each valve means in reverse sequence, thus transferring the fluid from the corresponding storage vessel into the alternating fluid system during transition from the low to the high pressure cycle. In this manner, fluid pressure may be stored and regenerated for use in alternating high and low pressure cycle fluid systems.

United States Patent 119 Mokadam et a1.

[ June 26, 1973 FLUID PRESSURE REGENERATOR AND PROCESS [75] Inventors: Raghuna'th G. Mokadam, Chicago;

Andrew A. Fejer, Oak Park, both of I11.

[73] Assignee: American Gas Association,

Arlington, Va.

22 Filed: Jan. 5, 1971 21 Appl. No.: 104,009

[52] US. Cl. 137/1, 60/3951 [51] Int. Cl. F02g 3/02 [58] Field of Search 62/6; 123/119 A;

[56] I References Cited UNITED STATES PATENTS 2,737,936 3/1956 Clarke 123/119 A 2,995,124 8/1961 Wutrich.... 123/119 A 2,751,924 6/1950 l-lynd 137/121 Primary ExaminerAlan Cohan Attorney-Alexander & Speckman [57] ABSTRACT pressure in the alternating fluid system. Each isolated storage vessel contains and stores a fractional portion of the fluid. Recovery of the same fluid portions may be achieved by providing communication of each storage vessel with the alternating fluid system through each valve means in reverse sequence, thus transferring the fluid from the corresponding storage vessel into the alternating fluid system during transition from the low to the high pressure cycle. In this manner, fluid presv sure may be stored and regenerated for use in alternating high and low pressure cycle fluid systems.

2 Claims, 3 Drawing Figures 45 95 1 1 73 V 65 v 7] 09 //?/i/ 45/ a a0 40 v i 32 33 34 PAIENIEnJum mm 3.741; 221

FIG?) 66 93 4 2,97 54 FIGZ 72 Z26 INVENTORSI RAGHUNATH G. MOKADAM ATT'YS FLUID PRESSURE REGENERATOR AND PROCESS DESCRIPTION OF PRIOR ART Historically, any fluid system having an alternating high and low pressure cycle has been faced with the requirement of exhausting its high pressure fluid during the transition of the system from the high to the low pressure cycle. In general, two things have been done with this exhaust fluid. Either the exhaust fluid has been blown out and wasted to the atmosphere or the exhaust fluid has been passed to an expander or turbine which converts this fluid pressure potential energy into mechanical work.

A major disadvantage of the above practices is that wasting to the atmosphere not only is inefficient but also leads to a contamination of the atmosphere through the introduction of possibly deliterious material. On the other hand, if this high pressure fluid is exhausted to an expander or a turbine and converted into mechanical energy, although some of the potential energy is reclaimed, much of it is still wasted through the inefficiency of the moving mechanical parts and the fact that the use of a mechanical device to expand gas in low temperature work presents considerable lubrication and leakage problems. In addition, the mechanical work is of no benefit to the system unless it is mechanically stored and transferred back to the system which results in further loss. Further, new fluid must be added to the essentially depleted fluid system for each cycle.

Several proposals have been advanced for handling the exhaust fluid from such alternating high and low pressure cycle systems.

For example, U.S. Pat. No. 3,119,237 discloses a method and apparatus in which several confined gas volum es interact with one another selectively controlling gas compression and expansion to produce a net refrigeration at different points in the system. A motor driven valve is employed to sequentially admit high pressure gas into separated sections whose volumes vary with the movement of a gas displacer component.

- The moving parts in this type of device present breakdown, lubrication and leak problems which seriously hamper their ability to increase efficiency. Further, this patent does not suggest the concept of pressure regeneration and thus results in waste of potential energy of high pressure gas.

U.S. Pat. No. 3,045,436 discloses the application of a first quantity of fluid to an expandable chamber while applying a second quantity of compressed fluid to hold the chamberunder pressure, and discontinuing the supply of the compressed fluid to permit the chamber to expand and cool the first quantity inside. Again this involves the direct interaction of two fluids through a movable means. A compressor is necessary and the idea of reusing fluid pressure produced in the system to increase the system efficiency is not suggested, and again there is no utilization of the potential energy of high pressure gas.

U.S. Pat. No. 3,431,746 discloses a reservoir which accepts effluent high pressure gas and causes it to compress the gas already in it. The compressed gas is cooled and allowed to expand, thus lowering its temperature. The cooled low pressure gas receives heat from a suitable heat exchanger before it is returned to the compressor or discharged into the atmosphere. This device does nothing to increase the efficiency of the system as a whole and wastes a considerable portion of the potential energy of the fluid.

None of these proposals has recognized that the potential energy of the high pressure exhaust fluid is reusable in the system itself. Rather, these proposals have transferred such exhaust fluid to separate systems in attempts to convert the pressure energy into mechanical energy, or, have merely indiscriminately recycled the fluid in the primary system. In either case, the optimum efficiency is not being obtained from the use of the exhaust fluid and therefore, the maximum benefit is not being realized from the entire system.

My invention is clearly distinguishable from the prior inventions because, unlike U. S. Pat. Nos. 3,119,237 and 3,045,436, its method does not involve the wasteful dissipation of thepotential energy of the high pressure fluids but rather involves the conservation of this potential energy by separate storage and isolation of a pressurized fluid in stepwise decreasing pressure sequence and then reuse of the same fluid to obtain pressurization in a reverse sequential manner. Also, unlike .U. S. Pat. No. 3,431,746, the present invention relates to a positive sequential storage of pressure energy at different isolated pressure levels and a later reuse of such pressure energy at definite determined points in the cycle of an alternating high-low pressure system.

Furthermore, my invention provides for reusing exhaust fluid to obtain efficiency which has not been obtained previously. My invention provides for the storage and later reuse in the same system of pressurized fluid which would ordinarily be blown down and wasted in the exhaust stroke of an alternating high and low pressure cycle system, thereby increasing not only the efficiency,-but also the healthfulness and economy of the alternating high and low pressure system. My invention also recognizes that storage and later reuse of fluid pressure energy in the same system is more efficient and economical than converting such energy directly into mechanical work by means of such devices as an expander or a turbine and then attempting to transfer such work to the fluid system. The retention of fluid pressure within a system as provided for by my invention therefore eliminates the number of moving parts prone to mechanical breakdown and the energy lost due to lubrication and leakage problems inherent at low temperatures when converting such pressure energy to mechanical work through devices such as an expander or a turbine.

DESCRIPTION OF THE INVENTION My invention comprises a novel method for regenerating the fluid pressure ordinarily wasted or used inefflciently outside an alternating high and low pressure cycle fluid system, to permit reuse of such fluid pressure to increase the efficiency of such a system. My invention also comprises a unique apparatus for accomplishing such fluid pressure regeneration. My process achieves fluid pressure regeneration by transferring the pressurized fluid normally exhausted from an alternating high and low pressure cycle system by a conduit means through a valve means to isolated storage means having an initial pressure level lower than the pressure of the alternating fluid system. In operation, the first storage means is opened to communication with the alternating fluid system and is initially at a lower pressure than the alternating fluid system. When the fluid pressure level in the first storage means is less than or equal to the fluid pressure level in the alternating fluid system, the pressurized fluid or a first portion thereof is isolated and stored in the first storage means. The second and any further succeeding portions of this pressurized fluid remaining in the fluid system may then be transferred successively, by a second conduit means through a second valve means to a second storage means, having a pressure level lower than the reduced pressure level of the alternating fluid system, thereby raising the pressure level in the second storage means to a point below or equal to the fluid pressure level in the fluid system, after which time the second valve means is closed. The next succeeding valve means is then opened, transferring the next succeeding portion of the pressurized fluid remaining in the fluid system by g a next succeeding conduit means to the next succeeding storage means having a pressure level lower than the further reduced pressure level of the alternating fluid system thereby raising the pressure level in the next succeeding storage means to a point below or equal to the pressure in the fluid system. The sequential transferring is repeated in succession until the desired amount of pressurized fluid transferred from the fluid system through succeeding valve means to isolated succeeding storage means has been stored.

During the transition of the fluid system from the low to the high pressure cycle, the stored fluid is returned to the fluid system. This return is initiated at the beginning of the transition of the system from the low to high pressure cycle by transferring the portion of the pressurized fluid from the storage means having the lowest pressure to the fluid system through the valve means in communication therewith. The emptied storage means is again isolated, and proceeding in like manner, the portion of the pressurized fluid contained in the number of succeeding storage means having increasingly higher final'pressure levels, is successively transferred to the fluid system, thus providing regeneration of fluid pressu're in an alternatinghigh and low pressure system.

Once restored to the system, this conserved fluid pressure can be used in several ways to increase the efficiency of the system, such as by doing work in returning the piston or inducing combustion of the fluid in the system.

Accordingly, an object of my inve'ntion'is to permit the reuse'of the pressurized fluid ordinarily wasted by exhaust from an alternating high and low pressure cycle fluid system to improve the efficiency and economy of the system producingsuch exhaust fluids.

Another object of my'invention is to provide fluid pressure regeneration having simplicity in operation obtained by independent, isolated storage means connected by closed conduits and having positively oper-- ated valves as the only moving parts, thereby substantially decreasing the problem of mechanical malfunction.

A further object of my invention is to provide a fluid pressure regeneration apparatus and process especially useful in low temperature alternating high and low pressure cycle fluid systems.

The invention will best be understood from the following description'when read in connection with the 'age means.

FIG. 2 isa schematic diagram of a multiple storage vessel fluid pressure regeneration apparatus according to one embodiment of this inventionv 3 FIG. 3 is a schematic diagram of my fluid pressure regeneration method and apparatus as used in connection with multiple alternating high and low pressure cycle systems.

The embodiment shown in FIG. 1 describes my pressure regeneration apparatus comprising a single storage vessel 16 connected by conduit 27 having a valve 37 to an alternating high and low pressure cycle system 63.

The pressurized fluid exhausted from the fluid system 63 during the transition from the high to low pressure cycle is transferred through conduit 27 and valve 37 into storage vessel 16. Storage vessel 16 has an initial pressure level lower than the pressure level in said fluid system 63 during the transfer. Valve 37 may be closed whenever the fluid pressure level in the storage vessel- 16 is less than or equal to the pressure level of the fluid System63. The maximum amount of pressurized fluid will be transferred by leaving valve 37 open until the pressure levels in storage vessel 16, and the fluid system 63 are equal. The fluid system 63 is then exhausted of remaining pressurized fluid sufficient to lower the pressure level in said fluid system 63 below the pressure I level of the pressurized fluid contained in storage vessel 16. Valve 37 is then opened and the pressurized fluid contained in storage vessel 16 is returned to fluid system 63.

Referring specifically to FIG. 2, the fluid pressure regeneration apparatus comprises in sequential communication storage vessels 10, l1, 12, 13 and 14, conduits 20, 21, 22, 23 and 24, respectively in communication with storage vessels 10, 11, 12, 13 and l4, positively operated normally closed valves 30, 31, 32, 33 and 34, respectively to control fluid flow through conduits 20, 21, 22, 23 and 24, and primary conduit 40 from each of the valves to the alternating high and low pressure cycle fluid system 63.

In the preferred embodiment of FIG. 2 prior to the storage cycle, storage vessels 10 through 14 must have initial pressure levels lower than the pressure level in said fluid system 63. The fluid system 63, in transition from high to low pressure cycle, exhausts a portion of pressurized fluid into primary conduit 40. Valve 30 is then opened positively, allowing a first fraction of this portion of the pressurized fluid to pass through conduit 20 into storage vessel 10. After the pressure level in storage vessel 10 equals or is slightly less than a first reduced pressure level in fluid system 63, valve 30 is closed and valve 31 opened. A next remaining fraction of this portion of pressurized fluid from the first reduced pressure level in fluid system 63 is now transferred through valve 31 and conduit 21 into storage vessel 11. After the pressure level in storage vessel 11 equals or is slightly less than the reduced pressure level in fluid system 63, valve 31 is closed and valve 32 is opened. The sequence is then repeated, transferring the next remaining fractions of this portion of the pressurized fluid from the reduced pressure level of fluid system 63 through the succeeding valves 32 and 33 respectively into the succeeding storage vessels 1'2 and 13, and the final remaining fraction of this portion of the pressurized fluid through the final succeeding valve 34 into the final succeeding storage means 14 until the desired amount of fluid contained in the fluid system has been stored in storage vessels through 14. The process of fluid pressure storage results in the pressurized fluid produced by fluid system 63 during transition from low to high pressure cycle being sequentially stored in isolated fractional amounts in order of decreasing pressure during the transition of said fluid system 63 from high to low pressure cycle. It is apparent from this embodiment, that the number of storage vessels and respective valve means required to store the portion of pressurized fluid from the fluid system may vary from two to infinity depending upon the amount of that portion desired to be stored and the fraction of that portion stored in each storage vessel. Due to the temperature zones in heat engines, the temperature of the fractions of fluid may be different.

In the preferred embodiment shown in FIG. 2 subsequent to the storage cycle but prior to the return of the pressurized fluid from storage vessels 10 through 14 to the fluid system 63, the pressure level in the final storage vessel in the storage sequence 14, is somewhat greater than the ambient or atmospheric pressure, but is the lowest of the fluid pressure levels in the storage vessels 10 through 14, and, is higher than a final reduced pressure level of the fluid system 63 at the beginning of the transition of said fluid system 63 from the low to the high pressure cycle. This occurs because any pressurized fluid remaining in the fluid system 63 after. thecompletion of the storage cycle is vented to the atmosphere or to a separate vessel thereby reducing the pressure level in the fluid system 63 to atmospheric or ambient. To begin the return of the stored fluid pressure from storage vessels 10 through 14 to fluid system 63, valve 34 is positively opened and the pressurized fluid contained in storage vessel 14 is allowed to flow back through conduit 24 and primary conduit 40, into the fluid system 63. When the fluid pressure level in storage vessel 14 is slightly greater than or equal to the increased pressure level in fluid system 63, valve 34 is positively closed. Valve 33 is then opened and the pressurized fluid stored in storage vessel 13 is allowed to flow through conduit 23 and primary conduit 40 into fluid system 63. Again, when the pressure level in storage vessel 13 is slightly greater than or equal to the increased pressure level in fluid system 63, valve 33 is positively closed. Continuing in reverse sequence to storage, the process of returning stored pressurized fluid to the fluid system 63 is repeated in the order of increasing stored pressure levels through valve 32 which communicates storage vessel 12 with fluid system 63 and through remaining valves 31 and 30 which respectively communicate the remaining storage vessels 11 and 10 with fluid system 63 until the pressurized fluid stored in the storage vessels 10 through 14, during the transition of the fluid system 63 from high to low pressure cycle, has been returned to the fluid system 63. Should the venting of the fluid system, prior to return as described above, not occur, it is apparent from this embodiment that return of the pressurized fluid to the fluid system from the storage vessels may be begun in reverse sequence from any storage vessel having a fluid pressure level higher than a final reduced pressure level in the fluid system. It is apparent however, that even in such a non-venting situation, all pressurized fluid stored will be recovered and used in the fluid system from which it was received and in other fluid systems which will accept fluid at lower pressure levels.

In the embodiment shown in FIG. 3, the fluid pressure regeneration apparatus comprises, in communication, alternating high and low pressure cycle fluid systems 61 and 62, both in transition from the high to the low pressure cycle, the conduits 25 and 26, the positively operated normally closed valves 35 and 36, and the enclosed storage vessel 15.

In the embodiment of FIG. 3 prior to the storage cycle, storage vessel has an initialpressure level lower than the pressure levels in said fluid systems 61 or 62. The fluid system 61 exhausts a portion of pressurized fluid into conduit and through the positively opened valve 35 into the storage vessel 15. At the same time, the fluid system 62 exhausts a portion of pressurized fluid into conduit 26 and through positively opened valve 36, into the storage vessel 15. Valves 35 and 36 are closed after the pressure level in storage vessel 15 is equal or slightly less than the reduced pressure levels in fluid systems 61 and 62. In this embodiment, the pressurized fluid contained in storage vessel 15 is recovered into separate fluid systems 61 and 62 during the transition of said systems 61 and 62 from low to high pressure cycles. To begin recovery, valves 35 and 36 are positively opened allowing the pressurized fluid contained in storage vessel 15 which has a pressure level higher than the pressure level in fluid systems 61 or 62, to be transferred to fluid systems 61 and 62. Valves 35 and 36 are closed after the pressure level in storage vessel 15 becomesslightly greater than or equal to the pressure level in fluid systems 61 and 62. It is apparent that the single storage vessel 15 in this embodiment could be replaced by a series of storage vessels and corresponding valves as described in the preferred embodiment shown in FIG. 2.

The volume of the fluid systems 61, 62 or 63 in FIGS. 1, 2 or 3 may change during the storage or recovery operations described in relation to those figures. It is preferable, however, that the storage vessels remain of constant volume and be thermally insulated.

In the embodiment shown in FIG. 3, the geometry of fluid system 61 may be different than that of fluid system 62. In such a case, it is possible to transfer a portion of pressurized fluid from fluid system 61 into storage vessel 15 or a series of storage vessels as shown in FIG. 2, isolate this fluid in such storage vessel or vessels, and then recover the pressurized fluid stored to fluid system 62 having a different geometry and volume than fluid system 61. Thus, potential energy from one fluid system may be stored and recovered to a fluid system of different geometry by use of the pressure regenerator.

By way of example only, my fluidpressure regenerating apparatus and process is useful in a directly coupled cooling system using the Moving Regenerator Engine (MORE), more fully described in U. S. Pat. application Ser. No. 91355, filed Nov. 20, 1970 Eric G. U. Granryd now US. Pat. No. 3,677,026 issued July 18, 1972. The MORE is an internal combustion heat engine having a movable heat-regenerative means within a substantially gastight gas chamber defined by a casing, the movable heat-regenerative means by its movement causing passage of enclosed gases in heat-exchange relation with the heat-regenerative means, and having an air intake conduit, exhaust conduit, fuel injection means, an ignition means and a pressure-responsive member. The MORE also comprises a process for conversion of chemical energy to mechanical energy by heating air within a substantially gastight gas chamber by passage in heat exchange relation with a moving heatregenerative means within the chamber, substantially continuous burning of an injected combustible fluid fuel during injection thereof. resulting in substantial increase in the average temperature-pressure relation of the gas within the gas chamber, expanding said gas chamber by movement of a pressure-responsive member, and heating the heat-regenerative means by passage of the combustion product gas in heat-exchange relation with the moving heat-regenerative means. In using the MORE engine with its pressure-responsive member directly coupled to the refrigeration compressor piston by means of a rigid bar or rod, it has become necessary to blow down high pressure, high temperature pressurized gas to the atmosphere with considerable loss of energy, or to blow such gas against moving pistons, or through wheels or vanes to produce mechanical work outside the cooling system. My fluid pressure regeneration apparatus, however, is connected to the combustion cylinder of the MORE to permit storage of this pressurized gas exhausted during the high pressure cycle of the MORE and reuse of such gas during the subsequent low pressure cycle in the MORE to produce work inside the MORE system.

Referring specifically to FIG. 2, the components of an embodiment of an internal combustion engine used with the pressure regenerating apparatus-of this invention are shown as shell casing 19, including side wall 38, first end 95 and second end 96 and with insulation 44 defining gas chamber 63 which is, generally cylindri- 64 or piston rod 54, or in some other way such that their operation is keyed to the movement of movable heat-regenerative means 83. Valve 71 may also be of a check-valve type permitting flow only into the chamber. Fuel injection means 43 provides communication from an external fuel supply reservoir to gas chamber 63. Fuel injection means 43 is equipped with carburetion means 73 which may be used to atomize the fuel if a liquidfuel is being used. Fuel injection means 43 may also be positioned on the right side of the regenerative means 83 as shown in FIG. 1, with fuel supply through rod 64 to hot volume 81.

Regenerative means shaft 64 extends through first end 95 and outer shell casing 19, penetrating first end 95 in fluid tight relationship, and sliding on contact sleeve 66. Regenerative means shaft is connected through suitable linkage means not shown to a power source which causes regenerative means shaft 64 to undergo a reciprocating movement. Secured to regenerative means shaft near the end thereof and within gas chamber 63 is movable heatregenerative means 83. Movable heat regenerative means 83 within gas chamber 63 is generally cylindrical in shape and extends substantially across the gas chamber. Movable heatregenerative means 83 is moved by the reciprocating movement of regenerative means mover shaft 64 and its movement is substantially parallel to the axis of gas chamber 63. Movable heat-regenerative means 83 divides gas chamber 63 into substantially two volumes, 'a first or cold volume 29 and a second or hot volume 81.

Pressure-responsive means 51, as shown in FIG. 2, is a piston 97. Piston 97 comprises second end 96 and extends in substantially airtight fashion across gas cham ber 63. Piston 97 is responsive to pressure changes within gas chamber 63 and permits expansion of said gas chamber. Connected to piston 97 is piston rod 54. Piston 97 may be linked by means of piston rod 54 to various types of apparatus for using mechanical energy. Piston 97, responding to the pressure of expanding gases within gas chamber 63 and to a return pressure exerted through piston rod 54, moves in a reciprocating fashion on a line substantially parallel to the axis of gas chamber 63. The return pressure exerted through piston rod 54 may be the result of energy stored in a fly wheel, fluid pressure in an exterior cylinder, or a wide variety of other means.

Prior to storage in the storage vessels of my fluid pressure regenerator, the cylinder of the MORE is filled up with high pressure, high temperature gas as shown in Number 63 of FIG. 2 of the drawings. All storage vessels 10 through 14 in my fluid pressure regeneration apparatus are at this time at a lower pressure level than the pressure level in the MORE cylinder 63. In addition, all the valves 30 through 34 in my pressure re generation apparatus are closedat this time. Storage of the pressurized gas from the MORE is started by opening a first valve 30 as indicated in the description of FIG. 2 and transferring a portion of the pressurized gas in the MORE cylinder 63, into the first storage vessel 10. The pressurized gas flows out of the MORE cylinder 63 into the storage vessel 10 until the pressure level in the storage vessel 10 is equal to or slightly less than the declining pressure level in the MORE cylinder 63, at which point the first valve 30 is closed and the second valve 31 is opened. As the pressure level is reduced in the MORE, the piston in the MORE cylinder may move. The valves of my pressure regeneration apparatus are operated by relating them to the operation of the MORE either by a mechanical connection to this MORE piston or by an electric timing device synchronized with the movement of this MORE piston. Only one valve is open at any one time, and the closing of one valve signals the opening of another valve which transfers a portion of theremaining pressurized gas to another storage means. This storage means then re-. ceives said gas until the pressure level in that storage means is equal to or slightly less than the further reduced pressure level in the MORE cylinder 63 at which time the valve is closed. When thedesired amount of pressurized gas from the MORE has been stored in the series of storage means 10 through 14 shown in FIG. 2, the small amount of remaining gas in the MORE is exhausted to the atmosphere, reducing the pressure level in the MORE cylinder 63 to the atmospheric pressure level which is below the pressure level in the storage means having the lowest relative pressure level, that is, the final storage means 14.

Recovery of the stored pressurized gas is begun after fresh air at atmospheric pressure is induced into the MORE cylinder by opening the valve 34 in connection with the final storage means 14 which allows the gas contained therein to flow back to the MORE cylinder 63 increasing the pressure level in the MORE cylinder 63 until it is equal to or slightly less than the reduced pressure level in the storage vessel 14. The valve 34 is then closed and the valve 33in connection with the next succeeding storage means 13 having a pressure levelhigher than the increased pressure level in the MORE cylinder 63 is opened. As the pressure level in the MORE cylinder'63 is increased, work is performed and the piston is moved in the opposite direction as in the storage cycle, and, as it moves, it acts positively to operate the valves of my fluid pressure regeneration apparatus. The remaining storage vessels 12 through are emptied in like manner until the desired amount of pressurized gas has been returned to the MORE cylinder 63.

Suitable fluids for use in my pressure regeneration process and apparatus include all gases or vapors, preferably air, natural gas, methane, ethane, propane, butane, or hydrogen.

Suitable materials for constructing my fluid pressure regeneration apparatus include, for the storage means, any type of plastic, metallic or organic substances which are impervious to gaseous and vaporous fluids and which are susceptible of being formed into definite enclosed volumes having a single aperture and capable of being thermally insulated. The closed conduit means may be constructed from any type of plastic, metallic or organic substances which are impervious to gaseous and vaporous fluids and'which are susceptible of being drawn and formed into elongated, enclosed tubular shapes and capable of being thermally insulated. The valve means likewise may be constructed from any type of plastic, metallic or organic substances which are impervious to gaseous and vaporous fluids and which are susceptible of being formed in various shapes. The valve parts must be capable of being fitted together'to form a fluid'tight 'seal while at the same time moving on each other with minimal friction. Preferable materials for constructing various parts are stainless steel, various stainless steel alloys, and ceramics.

The number of enclosed storage vessels used in my pressure regeneration apparatus and process depends upon the efficiency desired in the entire alternating high and low pressure fluid system and the cyclic speed required in the entire high and low pressure fluid system. The greater the number of storage vessels, or the larger the volume of the storage vessels used in my invention, the greater the corresponding possible increase in efficiency in the entire system. If the number of storage vessels is increased significantly, the volume of the individual storage vessels may be decreased. An increase in the number of storage vessels used will require a decrease in the number of cycles per minute at which the alternating pressure cycle fluid system and the related pressure regeneration apparatus will function. My pressure regeneration process and apparatus may suitably be operated up to about 1,000 cycles per minute. The minimum operating speed is not critical and obviously, the apparatus may be operated at very low speeds such as at 1 cycle per minute or even 1 cycle per hour. Operation between about 10 and 1,000 cycles per minute is preferred, and operation between about 100 and 500 cycles per minute is especially suitable.

The optimum initial pressures to be used in the individual storage vessels depend on the volume of the fluid system and the pressure ofthe pressurized fluid in the fluid system at the beginning of the transition of said pressure in the fluid system below atmospheric. The

only restrictions imposed on my invention in this regard are mechanical, depending on the type of work being attempted in the entire alternating high and low pressure cycle fluid system.

As an example only, usingan initial pressure of 5300 psf in an alternating high and low pressure cycle fluid system such as a heat engine having a cylinder volume of 0.7 cubic feet, it was determined that a pressure regeneration apparatus consisting of two storage vessels, each with volumes of 1.4 cu. ft. and an atmospheric pressure of 2,117 psf, yieldeda work recovery factor of 0.38. That is, 38 percent of the work which could possibly have been obtained by an ideal, isentropic, adiabatic expansion to atmospheric pressure of the pressurized fluid initially in the engine cylinder. This is work obtained from fluid pressure energy which'wouldhave otherwise been rejected and wasted by the fluid system by exhausting to the atmosphere.

My pressure regeneration apparatus consisting of four or five storage vessels, each having a volume equal to twice that of the cylinder of the heat engine, will permit recovery of approximately of the work potentially obtainable from the pressurized fluid normally exhausted by an alternating high and low pressure system such as the directly coupled MORE engine described above.

Work conducted by using the pressurized fluid exhausted from the MORE enginein an expander indicates that the 80% recovery factor made possible by my invention will more than double the cycle efficiency of a heat engine and coefficient of performance of a directly coupled refrigeration unit operating at 500 cpm. That is, the use of my invention will more than double the amount of work obtainable from the MORE per cycle, and as a result will also more than double the effective performance of the MORE in running a related cooling apparatus thereby producing double the total cooling effect.

While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof,- and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

I claim:

l. A method for fluid pressure regeneration useful in alternating high and low pressure cycle fluid systems comprising;

sequentially transferring during transition of said fluid system from a high to low pressure cycle a portion of fluid'from said fluid system in fractions to multiple storage means by transferring a first ceeding valve means to succeeding storage means,

said succeeding storage means having initial pressure levels lower than the pressure level in said fluid system at the time of opening of the respective valve means, closing succeeding valve means when the pressure level in succeeding storage means equals or is slightly less than the reduced pressure level in said fluid system after storage in the respective storage means; repeating said transferring until a final remaining fraction of said portion of fluid is transferred through final succeeding valve means to final succeeding storage means having an initial pressure level lower than the reduced pressure level in said fluid system after storage in previous storage means, closing said final valve means when the pressure level in said final storage means equals or isslightly' less than the remaining pressure level in said fluid system;

isolating said portions of fluid in said storage means;

lowering the pressure in said fluid system; and

returning to said fluid system said fractions of fluid contained in said multiple storage means by transferring in reverse sequence to storage through said respective valve means respective fractions of said portions of fluid contained in said respective storage means, closing said respective valve means in reverse sequence to storage after said respective fractions of fluid have been returned to said fluid system to increase the pressure in the fluid system during transition of the fluid system from a low to high pressure cycle.

2. The method of claim 1 wherein said fractions of fluid are at different temperatures. 

1. A method for fluid pressure regeneration useful in alternating high and low pressure cycle fluid systems comprising; sequentially transferring during transition of said fluid system from a high to low pressure cycle a portion of fluid from said fluid system in fractions to multiple storage means by transferring a first fraction of said portion of fluid through a first valve means to a first storage means having an initial pressure level lower than the pressure level in said fluid system, closing said first valve means when the pressure level in said first storage means equals or is slightly less than a first reduced pressure level in said fluid system, then transferring next remaining fractions of said portion of fluid through succeeding valve means to succeeding storage means, said succeeding storage means having initial pressure levels lower than the pressure level in said fluid system at the time of opening of the respective valve means, closing succeeding valve means when the pressure level in succeeding storage means equals or is slightly less than the reduced pressure level in said fluid system after storage in the respective storage means; repeating said transferring until a final remaining fraction of said portion of fluid is transferred through final succeeding valve means to final succeeding storage means having an initial pressure level lower than the reduced pressure level in said fluid system after storage in previous storage means, closing said final valve means when the pressure level in said final storage means equals or is slightly less than the remaining pressure level in said fluid system; isolating said portions of fluid in said storage means; lowering the pressure in said fluid system; and returning to said fluid system said fractions of fluid contained in said multiple storage means by transferring in reverse sequence to storage through said respective valve means respective fractions of said portions of fluid contained in said respective storage means, closing said respective valve means in reverse sequence to storage after said respective fractions of fluid have been returned to said fluid system to increase the pressure in the fluid system during transition of the fluid system from a low to high pressure cycle.
 2. The method of claim 1 wherein said fractions of fluid are at different temperatures. 